Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The most apparent immunologic role of the mammary gland is supply to antibodies to the neonate. In cattle the gland must be able to secrete large quantities of IgG antibodies over a short time period to supply the offspring with protection against systemic pathogens. This is accomplished by selective transfer of IgG from serum to the gland followed by eventual absorption by the neonate gut. In all mammals, the mammary glands provide IgA antibodies specific for pathogens or antigens which enter or invade the neonatal gut. An entero-mammary cell circulation provides the mechanism for conveying such specificity to the lacteal IgA antibodies. Some IgA antibodies may also be derived from the circulation so that the quantitative significance of serum derived versus locally produced IgA in different species requires clarifications. IgG and IgG lacteal antibodies ingested by the neonate, provide short-term systemic and long-term enteric humoral immunity to the neonate. In addition to providing passive immunity, at least swine IgG appears to have a regulatory role in the development of the systemic humoral immune system of the neonate. Such a phenomenon may be general for IgG antibodies transferred in colostrum or in utero. While passive antibodies and immunoglobulins may be most important for the neonate, the many other potentially anti-infectious elements transferred in colostrum and milk may also play important roles. 'Bifidus' factor particularly, but also lysozyme and lactoferrin are probably all important although more convincing experimental data will be needed to support this assumption. Studies of cells of the lymphoid and reticuloendothelial systems in milk are more recent and their role in the neonate remains to be convincingly demonstrated. In summary, the immunologic and anti-infectious roles of the mammary glands are (1) Supply of IgA antibodies against enteric antigens to the neonate on a 'long-term' basis throughout lactation; (2) Short-term supply of IgG (and IgA) in Group II and III mammals for eventual absorption into neonatal serum; (3) The supply of numerous nonspecific factors such as 'bifidus factor,' lactoferrin, and lysozyme throughout lactation; (4) Regulation of the development of humoral immunity by an apparent feedback mechanism involving maternal IgG; (5) Self-protection of the gland by sensitized T-lymphocytes acting directly or using lymphokines on macrophages; and (6) Self-protection of the gland by secreted antibodies that may act in complement-independent cytolysis, as opsoins for polymorphonuclear-leukocytes or directly as agents preventing colonization.
 ...
PMID:Immunologic aspects of breast feeding, antiinfectious activity of breast milk. 39 68

High titer, monospecific antibodies to human granulocyte myeloperoxidase, cathepsin G, elastase, lysozyme, and lactoferrin were conjugated with fluorescein and rhodamine and used for immunofluorescent staining of mature neutrophils obtained from 25 patients with acute and chronic leukemia. In 11 (44%) of the patients, two populations of mature neutrophils were detected. The abnormal cells were identified by complete deficiency of one or more markers and constituted 10%-100% of the total number of neutrophils. This immunocytochemical approach may permit recognition of mature cells derived from leukemic clones, and serial determinations of the ratio of normal to abnormal cells may be useful in the management of patients with leukemia.
 ...
PMID:Immunocytochemical identification of abnormal polymorphonuclear neutrophils in patients with leukemia. 40 Aug 91

Bronchial secretions from 207 children suffering from various pulmonary diseases and from 15 healthy controls were tested concentration of IgA, IgG, lactoferrin and lysozyme. The results obtained suggest that in many cases of chronic lung diseases in children the levels of lactoferrin and immunoglobulins, especially secretory IgA, are very low. In severe infections (cystic fibrosis, bronchiectases) significant increase of IgG concentration was observed.
 ...
PMID:Proteins in bronchial secretion of children with chronic pulmonary diseases. I. Relation to clinical diagnosis. 44

The concentration of immunoglobulins, lactoferrin and lysozyme we compared in bronchial secretions obtained from children with various chronic lung diseases. The IgG, lactoferrin and lysozyme, but not secretory IgA, concentrations were shown to be increased during chronic inflammatory response.
 ...
PMID:Proteins in bronchial secretion of children with chronic pulmonary diseases. II. Relation to bronchoscopic and bronchographic examination. 44 1

A simple and rapid method is described for the removal of lysozyme from human whole salivary supernatant. Saliva specimens were adsorbed with Micrococcus lysodeikticus. The saliva so treated was depleted of 95% of the lysozyme activity. Changes in total protein, lactoperoxidase, lactoferrin, immunoglobulin A, and the proportions of several anionic proteins were less than 10%. It is concluded that adsorption of saliva with M. lysodeikticus is a suitable procedure for the preparation of saliva that is selectively deficient in lysozyme.
 ...
PMID:Simple and rapid procedure for the selective removal of lysozyme from human saliva. 52 61

Lower incidences of infection among breastfed vs. bottlefed infants have been attributed, not only to bottle contamination, but to the presence of various antibacterial factors in breast milk. 3 of these factors, immunoglobulins, lysozyme, and lactoferrin, were quantitated from milk samples from well-nourished and under-nourished Indian women in various stages of lactation. An ancillary concern of this study was to determine whether iron supplementation in under-nourished lactating women might abolish the bacteriostatic mechanism of lactoferrin by altering its saturation in milk, thus interfering with its biological function. 250 women gave breast milk samples for study. In addition, 11 lactating women were given 200 mg of iron intramuscularly, and their milk samples were assayed. In the nonsupplemented women, the concentration of immunoglobulin A (IgA) was high in colostrum, with a mean level of 350 mg/100 ml, and fell rapidly during the first 4 weeks of lactation, to a mean level of 110 mg/100 ml. IgG concentration was slightly higher in colostrum than in mature milk. Lactoferrin concentration was very high in colostrum, with a mean level of 600 mg/100 ml, and fell progressively up to 5 months of lactation, stabilizing at a mean level of 180 mg/100 ml. Lysozyme content of colostrum was lower than that of mature milk and showed a progressive increase with duration of lactation; its highest level of 42 mg/100 ml was reached at 12 months. No significant differences in levels of immunoglobulins, lactoferrin, and lysozyme were found between well-nourished and under-nourished mothers. In women who received the iron supplements, at first the mean level of total lactoferrin was 240 mg/100 ml, 9% of which was saturated. No significant changes in concentrations of either total or saturated lactoferrin were found after administering the iron supplement.
 ...
PMID:Antimicrobial factors in human milk. 55 77

The ability of highly purified human leukocytic pyrogen (LP) to induce neutrophil lysosomal protein release is described. Human peripheral blood neutrophils isolated by Ficoll-Hypaque and dextran sedimentation were exposed to purified human LP. The specific granule-associated proteins, lysozyme and lactoferrin were selectively released, whereas primary granule (beta-glucuronidase) and cytoplasmic (lactic dehydrogenase) enzyme markers were not. Optimum release was observed after 45 min in the presence of Ca++ and Mg++. Cytochalasin B (5 microgram/ml) had no effect on LP-induced lysosomal enzyme release. Since the pyrogenicity of LP is dependent on prostaglandin synthesis, the effect of two potent inhibitors of prostaglandin synthesis on lysozyme release was studied. Both indomethacin and naproxen failed to inhibit specific granule protein release. These observations suggest that the concommitance of fever, elevated serum or urine lysozyme and hypoferremia may, in part, be explained by the interaction of LP and peripheral blood neutrophils.
 ...
PMID:Human leukocytic pyrogen induces release of specific granule contents from human neutrophils. 65 95

The "skin window" technique in which the horny layer of the skin is abraded with a high speed grinder has been used to study the appearance of proteins with antimicrobial activity in the fluid accumulating in damaged human skin. The fluid was absorbed into paper discs and protein levels measured by radial diffusion. The skin exudates contained about 45% as much IgG and IgM as the subjects' serum, but the amount of IgA (68% of the serum level) in the exudate was significantly greater, suggesting selective transport into the lesion. The fluid also contains complement proteins, lysozyme and lactoferrin. The methods used in this study may provide useful information about clinical situations in which susceptibility to cutaneous infection is increased.
 ...
PMID:Antimicrobial factors in the exudates of skin windows in human subjects. 82 75

The protective effect of breast feeding against infections is well proved by the experiences in underdeveloped countries and in industrial countries as well as shown by numerous investigations in several populations of different social structure. Various factors are meant to be responsible for this special property of human milk, the importance of which is to be discussed. The lysozyme and the lactoferrin are two different antibacterial factors well known since a long time, the former of which is mainly directed against grampositive organisms and against gramnegative ones only under special conditions. Lactoferrin is effective against E. coli and Staphylococcus as well. The neuraminic acid of which the human milk contains a larger quantity than cow's milk also inhibits the growth of E. coli and Staphylococcus. A further factor consisting of isomers of linoleic acid protects mice against lethal Staphylococcus - infections. The most important antibacterial principles of human milk are meant to be specific immunoglobulins, specially secretory IgA. The immunoglobulins are mainly important for the young baby in the early stage of life. The fecal bifidusflora specific for the breast-fed infant is also meant to be protective against several infections. The factors of human milk provoking this special kind of intestinal flora are to be discussed. In the artificial-fed infant bifidus flora like that of breast-fed one can arise by application of lactulose. Nowadays, bifidus-flora can probably be obtained by application of beta-lactose. It is suggested, that infants with bifidus-flora provoked by one of this means are protected against intestinal infections. The results of all investigations on mother's milk lead to the conclusion, that breast-feeding is the optimal kind of alimentation in the first time of life, not only concerning the composition of the food, but concerning protection against infections.
 ...
PMID:[The protective effect of human milk against infections and its potential causes (author's transl)]. 82 95

Lysozyme and lactoferrin levels were measured in 71 synovial fluids (SF) of patients with traumatic effusions, osteoarthritis, rheumatoid arthritis, pseudogout, septic arthritis, and gout, as well as in 91 synovial fluids graded according to their neutrophil count. Elevated lysozyme levels were found in all the inflammatory arthritides and also in osteoarthritis. Lactoferrin levels were not increased in osteoarthritis but displayed a close correlation to the extent of the inflammatory response as judged by SF neutrophilia. The ratio of lysozyme to lactoferrin decreased progressively with increasing SF neutrophilia. In vitro experiments showed that lactoferrin is released from neutrophils isochronously with lysozyme and beta-glucuronidase. Lactoferrin was not found in hyaline cartilage, a tissue known to contain lysozyme. These results are consistent with belief that SF lysozyme has a major derivation from both cartilage and neutrophils, and that lactoferrin arises only from neutrophils. These findings indicate that the simultaneous measurement of lysozyme and lactoferrin provides a potentially useful index of both joint inflammation and cartilage degradation.
 ...
PMID:Lactoferrin and lysozyme levels in synovial fluid: differential indices of articular inflammation and degradation. 83 40


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>